patch applied (ghc-6.6/testsuite): Catch exceptions while cleaning rather than checking for existence first

[Ian Lynagh]

Sun Sep 10 07:59:57 PDT 2006  Ian Lynagh <igloo at earth.li>
  * Catch exceptions while cleaning rather than checking for existence first
  As well as being generally a good idea, os.access('foo') seems to return
  true if foo.exe exists on Windows.

    M ./driver/testlib.py -1 +3